1. Field of the Invention
This invention generally relates to monitoring physiological parameters of a patient and more specifically to the monitoring of such parameters in patients who are geographically remote from a medical facility.
2. Description of Related Art
Monitoring of a patient's physiological parameters in a medical environment is an important element of patient diagnosis and treatment. Within a modern medical facility, such as a hospital, such monitoring is relatively easy to perform. The environment is controlled. The staff, including physicians, nurses, physician assistants and technicians, is qualified. Such facilities have equipment resources for enabling the monitoring of one or more patients for a variety of physiological parameters.
Unfortunately the advantages of a hospital environment with its resources and personnel do not exist at many trauma sites, such as those at accident scenes or at battlefield sites. First responders to an accident scene generally include an emergency medical technician (EMT). The EMT assesses the patient and, in conjunction with advice from medical personnel established by radio contact, initiates treatment. Typically the EMT stays with the patient during transport to a medical facility. The EMT can transfer his or her observations to personnel at the facility by interview and/or by written record.
An entirely different situation exists on a battlefield. On a battlefield a medic is attached to a particular unit. The medic treats a patient. When the medic completes treatment at the battlefield site, the patient is transported to another facility. However, the medic stays behind to attend to other patients. The medic's initial treatment protocol will be based on certain readings taken at the site. Then there are procedures for identifying the actions that were taken at the site. For example, if a sedative is administered, the medic may pin the syringe to the patient. Typically no interview occurs between the personnel at the medical facility, such as a field hospital, and the attending medic. Moreover, typically no information is recorded about the patient during initial treatment and transport for transfer to the field hospital.
Recently proposals have been made for personal monitoring systems for use in a battlefield environment. U.S. Pat. No. 6,198,394 (2001) to Jacobsen et al. discloses one such system for remote monitoring of personnel. This system utilizes a harness with a number of sensors to be worn continuously by a soldier. The sensors monitor a number of parameters including physiological variables. The harness carries a transmitting unit for transferring data to a central site.
U.S. Pat. No. 6,454,708 (2002) to Ferguson et al. discloses a portable remote patient tele-monitoring system using a memory card or a smart card. This system includes a multi-parameter sensor array applied to a patient's chest by means of a sensor band. The smart card or memory card stores measured data. Alternatively, a data logger carried by the patient receives the data. A base station receives the recorded information and transmits it to a remote monitoring site over a telecommunications link. The sensor band is disposable and has a limited life. For long-term monitoring, sensor bands may be replaced periodically.
U.S. Patent Publication No. 2004/0147818 (2004) to Levy et al. discloses a portable system for monitoring and processing patient parameters in multiple operational modes. Specifically a data acquisition processor receives data from sensors on a patient and processes that data. The processed data is communicated to a docking station with a portable monitoring unit in one operational mode or to a network access point in a wireless network in another operational mode.
As will be apparent, each of these proposals requires the use of bulky equipment. The Jacobsen et al. patent requires a soldier to wear a harness to be worn at all times. First, such a requirement requires the soldier to carry extra weight and to take precautions to avoid damaging the equipment during normal use. It is not likely that such a harness would be an acceptable alternative for application to a trauma patient on a battlefield or at another trauma site. Such apparatus is bulky, so it would be difficult to inventory such harnesses for multiple patients. In addition, medical personnel would have the additional burden of placing the harness on a trauma patient under adverse circumstances.
Each of these systems depends upon the availability of sophisticated communications links, such as those available in a hospital environment. They are not always available at a trauma site or on the battlefield. The use of smart cards or memory cards as suggested in the Ferguson et al. patent present problems because such devices are prone to being lost at a trauma site or during patient transport to a hospital or other central site. Further, only the data-measured at the trauma site is recorded.
What is needed is patient monitoring apparatus that includes a compact sensor and recording device that medical personnel on the battlefield or at a trauma site can readily inventory and apply to a patient in a positive, secure manner for recording various physiological data. What is also needed is such apparatus that facilitates use by medical personnel and that provides a continuum of data for use by personnel at a hospital or like facility.